1. Field of the Invention
The present invention relates to a circuit board provided to a marking material receptacle that houses a marking material for print.
2. Related Art
In recent years, there has been developed ink cartridges of a type equipped with a circuit board that has a storage device for storing data relating to the ink contained in the ink cartridge. Such circuit boards are equipped with terminals for receiving power, data for storage, etc. from a printer, or for sending stored data to a printer.
The following description of a conventional terminal arrangement makes reference to FIG. 12. Circuit board 500 has a first terminal row with a ground terminal 510 in its center, a data I/O terminal 520 to a first side thereof, and a read/write signal terminal 530 to a second side thereof; and a second terminal row, located above the first terminal row, with a power terminal 540 in its center, a clock signal terminal 550 to a first side thereof, and a chip select signal terminal 560 to a second side thereof.
Printer 580 is provided with contact pins 570 corresponding to each of these terminals 510-560; when the ink cartridge is installed in the mounting portion of the printer, terminals 510-560 come into contact with the corresponding contact pins 570 to enable power, data, etc. to be exchanged between the circuit board 500 and the printer 580. The ground terminal 510 is used to allow the printer to determine if the ink cartridge is correctly installed; ink cartridge installation is detected by sensing contact (electrical continuity) between the ground terminal pin of the printer 580 and the ground terminal 510.
However, in the past there has been the problem that in some instances electrical continuity is sensed, and ink cartridge consequently determined to be installed, even where terminals 510-560 and contact pins 570 are not in contact due to misalignment of the circuit board 500, etc. A resulting problem in such instances is that despite the determination that the ink cartridge is installed, the data stored in the storage device cannot be read.
In view of this problem, it is an object of the present invention to provide a terminal arrangement for a circuit board which permits accurate detection of contact with the terminals of the circuit board. It is a further object to provide a marking material receptacle affording accurate detection of whether the marking material receptacle has been installed.
To solve this problem, the invention in a first aspect thereof provides a circuit board comprising a storage device for storing data relating to a marking material for print. The circuit board according to the first aspect herein comprises: at least two ground terminals arranged on said circuit board at two edges thereof that are located on one axis thereof, and a plurality of terminals arranged on said circuit board, for read/write operations on said data relating to a marking material.
According to the circuit board of the first aspect herein, there are provided at least two ground terminals arranged on said circuit board at two edges thereof that are located on one axis thereof, thereby affording accurate detection of contact with the terminals on the circuit board.
In the circuit board of the first aspect herein, said plurality of terminals and said ground terminals may be arranged in a single row, with two of said at least two ground terminals being located at the outermost ends of said row. With this arrangement, contact with the terminals on the circuit board can be detected accurately.
In the circuit board of the first aspect herein, said plurality of terminals may be arranged to form a plurality of rows, with two of said at least two ground terminals being located at the outermost ends of one of said plurality of rows. Said plurality of terminals may include a clock signal terminal, with said clock signal terminal being located between two of said at least two ground terminals. With this arrangement, the clock signal can be stabilized. Further, said plurality of terminals may include a power supply terminal, with two of said at least two ground terminals being located at the outermost ends of a row different than the row that contains said power supply terminal. This arrangement prevents short-circuiting between the power supply terminal and the ground terminals.
In the circuit board of the first aspect herein, said plurality of terminals may include a power supply terminal and a control signal terminal, and said at least two ground terminals are not the terminals in closest proximity to said power supply terminal. This arrangement prevents short-circuiting between the power supply terminal and the ground terminals.
In the circuit board of the first aspect herein, said plurality of terminals may include a data I/O terminal, a power supply terminal, a select signal terminal, a read/write control signal terminal, and a clock signal terminal, and said plurality of rows may have
a first row wherein said data I/O terminal and said select signal terminal are located to either side of said power supply terminal, and
a second row wherein said read/write control signal terminal and said clock signal terminal are located between said two ground terminals,
said first row being located closer to the center of said circuit board than is said second row, and with said terminals in said first row and said terminals in said second row arranged in alternating fashion. This arrangement prevents short-circuiting between terminals, and also prevents unwanted contact of terminals.
In the circuit board of the first aspect herein, said plurality of terminals may be arranged at intervals of approximately 1 mm in the direction of formation of said rows.
In a second aspect, the invention provides a circuit board comprising a storage device for storing data relating to a marking material, and provided to a marking material cartridge having a substantially rectangular shape. The circuit board according to this second embodiment comprises: two ground terminals arranged on said circuit board at two edges thereof along one side thereof; and a plurality of terminals arranged parallel to one side of said circuit board, and used for storing said data.
According to the circuit board of the second aspect herein, two ground terminals are arranged on the circuit board at two edges thereof, thereby affording accurate detection of contact with the terminals on the circuit board.
In the circuit board of the second aspect herein, said plurality of terminals may form a plurality or rows parallel to one side of said circuit board, and said two ground terminals may be arranged at the outermost ends of one of said plurality of rows. Said plurality of terminals include a clock signal terminal, a control signal terminal, and a power supply terminal, with said two terminals being located at the outermost ends of a row that is different from the row that includes said power supply terminal, and that includes said clock signal terminal. This arrangement affords working effects similar to the circuit board pertaining to the first aspect.
In a third aspect, the invention provides a marking material receptacle configured to be used with a printing device. The marking material receptacle pertaining to this third aspect comprises: a receptacle chamber for housing said marking material; and a circuit board having a storage device for storing data relating to the marking material housed in said receptacle chamber, said circuit board having a plurality of terminals arranged thereon along one axis thereof, and at least two ground terminals arranged on said circuit board at two edges thereof that are located on one axis thereof.
In the marking material receptacle pertaining to the third aspect herein, there is provided a circuit board having arranged thereon at least two ground terminals, located at two edges thereof that are located on one axis thereof, thereby affording accurate detection of whether the marking material receptacle has been installed. The marking material is used for printing texts and/or images.
In the marking material receptacle pertaining to the third aspect herein, said plurality of terminals and said terminals may be arranged in a single row, with two of said at least two ground terminals being located at the outermost ends of said row. Said plurality of terminals may be arranged to form a plurality of rows, with two of said at least two ground terminals being located at the outermost ends of one of said plurality of rows. These arrangements as well afford accurate detection of whether the marking material receptacle has been installed.
In the marking material receptacle pertaining to the third aspect herein, said plurality of terminals may include a power supply terminal, control signal terminal, and clock signal terminal, with two of said at least two ground terminals being located at the outermost ends of a row that is different from the row that includes said power supply terminal, and in the same row as said clock signal terminal. This arrangement stabilizes the clock signal, and prevents short circuiting between the ground terminal and power supply terminal.
In the marking material receptacle pertaining to the third aspect herein, said plurality of terminals may include a data I/O terminal, a power supply terminal, a select signal terminal, a read/write control signal terminal, and a clock signal terminal; and said plurality of rows may have a first row wherein said data I/O terminal and said select signal terminal are located to either side of said power supply terminal, and a second row wherein said read/write control signal terminal and said clock signal terminal are located between said two ground terminals, with said first row being located closer to the center of said circuit board than is said second row, and with said terminals in said first row and said terminals in said second row arranged in alternating fashion. This arrangement prevents short-circuiting between terminals, and also prevents unwanted contact of terminals.
In the marking material receptacle pertaining to the third aspect herein, said plurality of terminals may be arranged at intervals of approximately 1 mm in the direction of formation of said rows. While incorrect installation of the marking material receptacle may result in faulty contact of terminals on the circuit board, with this arrangement, any faulty contact of terminals on the circuit board can be detected appropriately by means of situating the ground terminals at both edges or the outermost edge of the circuit board.
In the marking material receptacle pertaining to the third aspect herein, said marking material receptacle may be an ink cartridge, or a toner cartridge. In either case, accurate detection of cartridge installation will be required.